Typewriting machine



A. W. SMITH.

TYPE/WRITING MACHINE. APPLICATION FILED IuNE II, I92I.

1,435,669. Imm No.. M1922.

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WITNEEEEE INVENTIJR MM j HIE ATTEIRNEY A. W. SMITH.

TYPEWRITING MACHINE.

APPLICATION FILED IuNE II, I92I.

Patented Nov. M, 1922.

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|NVENTR WITNEEEEE HIE ATTRNEY A. W. SMITH. Y

TYPEWRITING MACHINE.

APPLICATION FILED JUNE II, |921. 19435,@69, Patented Nov. M, 1922.

Y WITNEEEEE INVENTR my Mwave HIE ATTEIRNEY Patented Nov. ili, i922..

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.entran statins 'ARTHUR w. slams, or Nnw YORK, N. Y.,Ass1eNon To REMINGTON 'rvrnwnrrnn COMPANY, or rmoN, Naw vonk, A CORPORATION or Nnw Yoan TYPEWRITING MA.

Application filed .Yune 11,

To all who-m. t may concern:

Be it known that ARTHUR W. SMITH citizen of the United States, and resident of the borough of Manhattan, lcity of New York, in the county of New York and State of New York, have invented .certain new and useful Improvements in Typewriting Machines, of which the following is a specification.

My present invention relates to carriage feedlng or escapement devices for typewriting machines, and its object, generally stated, is to provide new and improved devices of the character specified and which are part-icularly adapted to cure defects commonly found in many escapement mechanisms heretofore constructed.

To the above and other ends which will subsequently appear'my invention consists in the features of construction, combinations of devices and arrangements of parts hereinafter described and particularly pointed out in the claims.

In the accompanying drawings illustrating the preferred form of my invention,

Figure 1 is a fragmentary front to rear vertical sectional view of a typewriting ma- Y chine embodying my invention.

Figure 2 is a fragmentary vertical sectional view taken on a plane indicated by the dotted line 1-1 in Fig. 1 and looking forward in the direction of the arrow at said line, said Fig. 2 being drawn on an enlarged scale.

Figure 3 is a horizontal sectional view taken on a plane indicated by the dotted line 2-2 in Fig, 2 and looking downward in the direction of the arrow.

Figure 4 is a fragmentary sectional view corresponding to Fig. 2 but showing the parts as they appear when a printing key 1s depressed, some of the parts in Fig. 2 being omitted from Fig. 4 and other parts being sectioned away.

Figure 5 is a fragmentary horizontal sectionalview taken' on a plane indicated by the dotted line 3-3 in Fig. 4 and looking downward. g

Figure 6 is a horizontal sectional view taken on a plane indicated by the dotted line 4 4 in Fig. 2 and looking downward.

Figure 7 is a vertical sectional view taken on planes indicated by the dotted hne 5-5 in Fig. 2 and looking in the direction of the arrow at said line.

1921. serial No. marea.

Figure 8 is a vertical sectional view corresponding to Fig. 2 butl showing the parts as they appear when the space bar is depressed, some of the parts shown in Fig. 2 being omitted from F ig. 8 and other parts being sectioned away.

t Figure 9 is a fragmentary horizontal sectional view taken on a plane indicated by the dotted line 6 6 in Fig. 8 and looking downward.

Figure 10 is a fragmentary sectional view taken on a 1plane indicated by the dotted' line 7-7 in ig. 7 and looking in the direction of the arrow at said line.

Figure 11 is a view showing the dog rocker detached and with its parts spread or separated.

My invention is shown applied to a typewriting machine, which, as appears from Fig. 1, includes a main frame comprising side plates 1 connected at the front by a U- shaped frame 2 that encloses the keyboardy and at the rear by a cross plate not shown. Arranged to reciprocate above the main frame is a traveling carriage comprising an inclined bar 3 provided at its ends with forwardly extending bars 4, said carriage being constantly urged leftward by spring drum mechanism preferably of the character disclosed and claimed in the application of E. E. Barney, Serial No. 364,644, iiled March 10, 1920. The top and bottom of the bar 3 are formed with oovedseats 5 which receive sets of antiriction rollers 6. rlhe upper set of rollers 6 co-operates with a grooved seat formed in a stationary guide bar 7 which extends crosswise of the machine and is secured by screws 8 to the upper end portion of an angular bed plate 9 which is suitably secured to the side plates 1. The guide bar 7 is lixed to the top of the vertically disposed portion of the bed plate 9, said plate having a forwardly extending horizontal portion which terminates in an upward extension 9a formed with a grooved runway or seat for the lower set of antifriction rollers 6. Journaled on the traveling carriage 3, 4 is a roller platen 10 with whose front face co-operate type bars or printing instrumentalities 11. The set of type bars are arranged in an arc of a circle below the platen and are normally horizon? tally disposed, their free ends resting on a pad 12 mounted on a curved rest or support 13. Said type bars are pivoted on a pivot wire 14 which is common to all of the set and is mounted on a vertical type bar Support or segment 15. Forward of its pivot each type bar is provided with a. contact face 16 for co-operation with the carriage feeding or escapement devices, and is formed below its pivot with an inclined or cam slot 17. Engaging with the slot 17 1s a headed pin 18 projecting laterally from the free end of the long arm of a bell crank 19, the set of bell cranks 19 being arranged in guide slots 2O formed in the rear portion of the support 13, the bell cranks having a common pivot wire 21 mounted on said support. The shorter arm of each bell crank 19 is connected by a link 22 with an angular lever 23 pivoted at 24 in a sub-frame 25 detachably mounted in the lower portion of the main frame. Each angular lever 23 is provided with a headed pin 26 which engages in a slot 27 formed in the rear arm of a key lever 28, the set of key levers extending forward and being pivoted on fulcrum rods 29 mounted in the sub-frame 25. Each key lever terminates at its forward end in an upright stem portion which is provided with a cap or key 30. When one of the printing keys 30 is d epressed it will through the described train of connections operate the associate type bar 11, said type bar being swung upward and Y rearward into operative contact with the platen and the paper thereon.

During printing movements the type bars will actuate the carriage feeding mechanism or escapement devices to which my present invention more particularly relates and which are connected with the carriage by connecting 4devices which are the invention of John H. Barr, being disclosed and claimed in his application Sr. No. 423,629, filed November 12, 1920, Briefly described, said connecting devices comprise a. feed rack 31 mounted on the carriage and normally intermeshing with a feed pinion 32 supported on the front end by a horizontal shaft 33 which co-operates at its ends through sets of anti-friction balls (not shown) with stationary ball seats or bearing members 36 and 40 supported on the bed plate 9. The shaft 33 is provided with a flange 33a and an enlarged bearing portion 33", the pinion 32 being loosely mounted on the shaft forward of -said portion 33", a circular retaining wire 43 preventing forward displacement of said pinion. An escapement wheel is provided with pointed teeth 46 beveled at their rear faces at 47, said escapement wheel being mounted on the bearing portion 33" of the shaft 33 and held in fixed relationship therewith by rivets 48 which pass through openings formed in the escapement wheel and in the flange 33a and rigidly connecting the escapement whrel with said flange. Said escapement wheel and flange project upward through an opening 9" in the body portion of the bed plate 9. The loose feed pinion 32 and the escapement wheel 45 are normally connected by devices comprising a pawl 49 having a tooth that co-operates with the teeth of the pinion 32, said pawl carrying a pointed pin 52 extending rearward through a slot in the escapement wheel 45. The pawl 49 is pivoted on a pin 54 carried by the escapement wheel 45, and is constantly pressed toward the pinion 32 by a spring 56. Movements of the traveling carriage are transmitted through the feed rack 31 to the feed pinion 32, and leftward turning movements of said feed pinion are normally transmitted through the pawl member 49 to the escapement wheel 45 and its shaft 33. The construction is such that the tooth of the pawl member 49 will bob in and out of the teeth of the pinion 32 as said pinion rotates backward, so that its movements will not be communicated to the escapement wheel and its shaft, which remains stationary during return movements of the carriage. Carriage releasing devices comprise a sleeve 59 slidably mounted on the shaft 33 behind the escapement Wheel and provided with flanges 60 and 61, the front flange 6() being beveled as indicated at 62 for co-operation with the pointed pin 52.. Sliding movements of the sleeve 59 are controlled from a release key lever 66 pivoted on the carriage and provided with a nose 67 operative on a release bar 70 suspended from the carriage frame. The bar 70 is adapted to actuate a lever member comprising arms and 76 which engage loosely with the sleeve 59 between its flanges and is effective to cause the beveled surface 62 acting through the pin 52 to swing the pawl 49 out of engagement with the pinion 32 and disconnect the escapement wheel 45 from the carriage, which will thus be released so that it may move freely leftward as set forth Amore fully in the aforesaid application, Serial No. 423,629.

My present invention more particularly relates to improved escapement dog mechanism which is provided to co-operate with the circular. rack member or escapement wheel 45. Said dog mechanism comprises an improved and Ysimplified three-dog es' capement, the three dogs being mounted on a carrier or rocker which is caused to vibrate when one of the printing keys is actuated, such vibration resulting in two of the dogs co-operating with the escapement wheel to effect an ordinary feed or no-drop of the carriage, that is, a feeding movement during the lreturn stroke of the actuated printing key. The third dog is only brought into use lduring the actuation of the space bar or key and at such actuation co-operates with the escapement wheel and with the normally engaged dog to cause a reverse feed of the carriage, that is, one in which the carriage movement takes place during the lll depression of the space key. They reverse feeding or full-drop takes place independently of the movement of the dog carrler or rocker, said carrier remaining motionless during the reverse feeding movement effected by the space key, the actuation of the latter causing a movement only of a supplementary part which is mounted on the main dog rocker and provides a bearing or support for the third do as wellis for the normally en a ed do y provi ing an escapement megchnism bf the character described the defect in typewriting commonly called spreads77 or printing characters in places which should be blank spaces, has been practically eliminated due to the prompt response of the escapement mechanism when the space key is operated, as fully explained hereinafter, in connection with the specific and detailed description of the preferred form of my improvements.

As appears from Figs. 1-4, 7, 8 and 11 there is provided a dog carrier or rocker 77 which is plate-like in form and may be of sheet metal, having at the ends of its lower side rearwardly bent parallel ears 78 which are formed with conical depressions or seats 79 and one of which receives the pointed or conical inner end of a screw pivot 80 and the other of which receives the pointed end of a pivot pin 81. The bearing or supporting devices 80 and 81 are mounted at the lower ends of downwardly extending parallel arms 82 which are arranged at opposite sides of the opening 9b in the bed pla-te 9 and may be cast integral with said plate. The screw 80 and pin 81 project inward toward each other from their respective supports, the screw 80 being locked or maintained in adjusted position by a check nut 83 while the pin 81 is maintained in desired position by a set screw 84 which is threaded up through the lower end of the associate arm 82. The carrier proper 77 is thus pivotally supported below and substantially in the plane of the escapement wheel 45 and so that it may swing or vibrate fore-and-aft of the machlne and transversely of said escapement wheel. or rocker plate 77 and preferably integral therewith is a holding or fixed dog 85 which is preferably a part of the carrier or rocker plate 77 bent or inclined forward away from the general plane of the rocker at an angle thereto so that the rear or working face of the dog 85 is in effect beveled for co-operation with the teeth of the escapement wheel. The upper part of the plate 77 is formed at its right-hand side (or at the left when Viewed from the rear as in Figs. 2, 4 and 8) with an upwardly inclined lug 77a which has pivoted to it at the rear side on a headed shoulder screw 86 an additional or secondary carrier part 87 formed preferably of sheet metal and having its lower left-hand portion At the upper part of the carrier" 87 off-set rearward by means of a-shoulder or angle portion 87b so that the off-set portion 87a is spaced away from the rear face of the main or primary carrier part 77 to provide a recess or pocket. T he part 87 is provided with a hook 88 which is bent around the front face of the plate 77 at the left-hand side and co-operates therewith to guide the plate 87 in its swinging or pivotal movements about the center 86, preventing the plate 87 from .separating unduly from the plate 77 toward the rear. Independent swinging movements of the plate 87 are normally limited by stop devices comprising a screw 89 threaded into the plate 77 from the rear and provided with a check nut 9() which locks the screw 89 in adjusted position, the end of the check nut being screwed in against the rear face of the plate 77. The screw 89 and the check nut 90 pass through an enlarged hole or opening 91 cut in the portion 87 of the carrier part 87, 87a, and the sides of said hole co-operate with the outer surface of the nut 90 to limit swinging movements of the secondary carrier part on its pivot 86. Housed or loosely confined in the recess between the rear face of the part 77 and the front face of the part 87b are two dogs or detent members, namely, a stepping dog` 92 and a third dog 93 pivoted respectively on studs 94 and 95 fixed to and projecting forward from the carrier part 87. The dog 92 is of ordinary construction, its upper end having the usual toothed form. The dog 93 comprises a tooth 93, a nose 93" projecting laterally from the body portion, and a thin neck 93c connecting the tooth 93u to the body portion. The dogs 92 and 93 are loosely mounted on their respective studs or pivots but are prevented from accidental displacement therefrom by the face of the plate 77 which is normally' contiguous to said dogs. Viewed from the rear the steping dog is arranged at the left of the third og and has its pivot 94 above the pivot 95 of said third dog, both these pivots being at the same side or to the right of the pivot 86 of the part 87 on which the dogs 92 and 93 are mounted. The stepping dog is provided with a tail/portion 96 and this tail portion and the opposite face of the third dog are recessed to provide a recess or seat for a coiled expansion spring 97 which reacts on both the dogs and tends constantly to throw their upper end portions, which are their engaging portions, toward the right as viewed from the rear. The pivotal movements of the dogs 92 and 93 on the studs 94 and 95 are limited in extent, each dog serving as a stop for the other in one direction while the stop for the stepping dog 92 in the opposite direction is provided by the shoulder 87". The side of the hook 88 serves as a. stop to limit pivotal movements of the third dog in opposite direction. Said third dog terminates at its upper end in a forwardly extending or off-set portion 93 which provides a tooth or detent device through which the third dog may co-operate with the teeth 46 of the escapement wheel as hereinafter appears. Normally, however, the tooth 93 is maintained out of the path of the escapement wheel teeth7 the rear face of the escapement wheel being cut away to provide a circular groove or track indicated at 98 in which the forwardly off-set tooth 93 is received, the groove having its center in the axis of the escapement wheel and being inside the radially disposed teeth 46 thereof.

It will be observed more especially from a comparison of Figs. 7 and 8 that the cutting or formation of the circular groove or depression 98 results in an unsual shape or formation of the escapement wheel teeth 46 giving said teeth a sort of rearward overhang or projection back of the bottom or vertical face of the depression 98. In other words the radially-projectinor teeth 46 have engaging portions which offset laterally or rearwardly from the body or web of the wheel. Normally the tooth 93a is held up in position to co-operate with the groove or cutout 98, and the stepping dog 92 is held up in engagement with the teeth of the escapement wheel by means of a draw spring 99 the lower end of which is hooked through a hole in an ear 87 bent off rearwardly at right angles on the lower end of the carrier part 87, 87. The upper end of the spring 99 is anchored to an arm 100 which is oil'- set rearward and inward from a bracket member or frame 101 which is secured by screws 102 to the front face of one of the lugs or arms 82. Besides the arm 100 which projects from the upper part of the bracket member 101 the latter also comprises an arm 103 projecting forward from the lower end of the bracket and at right-angles to the body portion thereof. The spring 99 tends constantly to swing the carrier part 87 upward about its pivotal center 86 and normally maintains the lower side of the hole 91 in contact with the under side of the nut 90 as clearly shown in Fig. 2. It will be apparent that with the part 87 thus held from independent turning movements by the stop device 90 the action of the spring 99 will be transmitted to the dog rocker as a whole and will tend to swing the part 77 forward on its pivot 80 and 81. This forward swingor movement of the entire dog carrier or rocker is limited by a stop arm 104 which projects inward or leftward from the right-hand arm 82 at right-angles therefrom, the inner end of said arm 104 terminating in a rearwardly bent portion 105 which provides a stop proper with which the front face of the carrier 77 may contact as shown clearly in Fig. 3. The opposite end "wheel, as shown clearly in Figs. 2 and 3,

and will arrest the escapement wheel and the traveling carriage with which it is connected, preventing the carriage from being drawn leftward by the motor or spring drum mechanism not shown herein but which may be of any suitable construction. The two-part dog carrier or rocker and the parts mounted thereon are adapted to be vibrated or swung to-and-fro in a direction fore-and-aft of the machine through the operation of the printing keys 30, movement from the printing, keys to the dog rocker being transmitted in the present instance through the contact faces 16 of the type bar 11. Said contact faces are adapted to coopcrate with the front edge of a curved universal bar 108 (Fig. 1) which is housed in a seat or depression 109 in the rear of the type bar segment 15. The universal bar mechanism is preferably of the construction dis-l closed in the application of Edwin E. Barney, Ser. No. 427,589, filed December 1, 1920, and need be but briefly described herein. Near its ends the universal bar 108 has rearward extensions 110 which are pivotally connected at 111 with crank arms 112 fixed to a shaft 113 from which said crank arms project upward, said shaft also being provided with a central rearwardly extending crank arm 114. The lower middle portion of the universal bar 108 is provided with a rearwardly extending arm 115 carrying a contact device 116 which is adapted to engagel with the point of the adjustable screw 89 carried by the dog rocker. The arm 115 has a downwardly extending lug 117 formed with an open mounted slot 118 that is engaged by a pin 119 projecting laterally from the upper free end of a crank arm 120 fixed to an axle device 121 which also carries a rearwardly extending crank arm 122. The crank arms 122 and 114 are connected by a link 123 which together with the crank arms 114 and 122 and the crank arms 112 and 120 synchronize the movements of the universal bar frame comprisingthe universal bar proper 108 and its rearward arm or extension 115. The pivotal supports 113 and 121 of said frame are mounted on a bracket member 124 to which the type bar segment 15 is secured, both said segment and its supporting bracket 124 being subjected to case von the bracket member 124.

Macnee I shifting movements, the result being that the universal b-ar at lts front edge is always 1n position normally to receive actuations from the contact edges 16 of the type bars.

The universal bar frame is provided with a coiled restoring spring 125 which is hooked over a pin 126 projecting upward from the arm 115, the forward end of said spring being connected to an adjustable anchorage 127 mounted on a pin oil/screw 128 supported 125 normally maintains the universal bar in contact with the front wall of the depression 109 and at this time the contact device or screw 89 on the dog rocker is contiguous to the contact device 116 of the universal bar, the dog rocker of course being maintained in this position normally by the spring 99. When one of the printing keys 30 is depressed, it acts through the train of type bar actuating devices to swing the connected type bar to operative position in contactive engagement with the platen 10 and causes the contact face 16 of said type bar acting against the universal bar 108 to move the universal bar frame rearward against the pull of its spring, the movement being transmitted through the screw 89 to the dog rocker which will be swung rearward from the Figs. 1-3 position to the Figs. 4-5 position. As a result, the stepping or loose dog 92 will swing rearward out of engagement with the escapement wheel tooth 46 and the beveled holding dog 85A will be brought into engage-ment with the front edge or corner of said wheel tooth. The parts are so related that this swinging movement of the dog rocker due to the depression of the actuated printing key 30 results in no drop or substantially no drop when the stepping dog disenga-ges from the escapement wheel andthe holding dog engages therewith'; that is to say, the escapement Wheel will not move to any substantial extent and consequently there will be no substantial movement of the carriage in printing or letter feed direction. When the stepping dog has swung rearward clear of the escapement wheel the spring 97 will become effective to swing said dog rightward as viewed from the rear, the dog turning on its fpivot 94 independently of the dog carrier and passing from one end of its movement to the other. or from contact with the shoulder 87b into contact with the stop or nose 93h on the third dog 93. When thus arrested by the nose 93b the step-ping dog 92 will be in register with the tooth space to the right of the wheel tooth 46 with which said stepping dog was just previously engaged` as viewed in when the printing key is released and the dog rocker swings forward toward normal position under the impulse of the spring 99, the escapement wheel When freed frOm The spring Fig. 4. Consequently,-

the control of the holding dog 85 will turn in the direction of the arrow (Fig. 4) causing the tooth or working face of the ,stepping dog to be acted on by the advancing wheel. tooth 46 and swung about its pivot 94 and against the pressure of the spring 97 until arrested by contact Vwith the stop device or shoulder 87". This results in the completion of the escapement movement and the consequent advance of the traveling carriage in letter feed direction to the extent of one unit. of movement, the entire letter feed or substantially the entire letter feed or unit of movement taking place during the upstroke of the printing key. In other words, during the operation of the print-- ing keys as described, the dog rocker and the two dogs 92 and 85 will co-operate with two successive teeth of the escapement wheel to provide an ordinary or no-drop' escapement for the carriage, that is, an escapement which affords step by step letter feeding movements of the carriage during the return movement or upstroke of the printing keys, the carriage remaining substantially motionless during the downward stroke or depression of the printing keys and the printing stroke of thev type bars. It will be observed that during the described operation of the carrier or rocker and dogs under the actuation of the printing keys the relationship between the carrier parts 77 and 87 will not be affected, the carrier part 87 being maintained with the under side of the hole 91 in contact with the inner side or face of the nut 90. `It will be further noted that the working face of the wheel tooth and of the stepping dog 92 are straight, the former of course being always radial of the wheel while the working face of the dog is radially disposed to the wheel normally. The backs of the teeth of both wheel and dog are beveled for clearance purposes to insure unobstructed action of the parts. On the other hand, thefholding dog 85 is beveled on its working face and provides the usual advantages of a beveled dog escapement.

For the purpose of preventing spreads means are provided for operating the carrier part 87 from the space key or bar of the machine and independently of movement by the carrier part 77, so as to cause the stepping dog 92 and the third dog 93, 93a to co-operate with the escapement wheel to cause the feed of the carriage to take place during the depression of the space key, giving in e'ect what-is commonly called a reverse feed. During this operation .the main carrier part 77 remains quiescent, serving merely as a pivotal support for the carrier part 87. The space key in the present instance is in the form of a bar 129 which as will be understood from Fig. 1 extends from side to side the machine forward of the printing keys land provides a cross connection for two space bar levers 130, the bar 129 connecting the front ends of said levers which are arf ranged in parallelism and at their ends are fixedly secured to a rock shaft 131 bearlng 1n brackets 132 fixed to and extending downward from the sub-frame 25. The pair of levers 130 (of which only the left-hand. one is shown) and the cross bar 129 constitute with the rock shaft the spacing frame. Arranged about midway of the length of said rock shaft and extending rearward therefrom is a curved arm 133. The forward end of said arm is bifurcated or split providing jaws 134 which surround the thickened or enlarged middle portion of the rock shaft and are drawn toward each other by a screw 135 to clamp the arm or bar 133 fixedly to the rock shaft so that it participates in rotary movements thereof under actuation of the space key or bar 129. D'ownwa-rd actuations of the space key are limited by a stop device 136 secured to the frame part 2. The rear portion of the arm 133 is curved upward and forward and terminates in an enlargement or head 133f. The head 133a normally underlies the forward arm of an actuating member or lever 137 which is pivoted at 138 on the bracket arm 103. The pivot 138 is as shown in Fig. 2 preferably a headed and shouldered rivet which is fixed to the arm 103, the lever 137 turning freely on the shouldered portion of said rivet and bein held against sidewise displacement by the ead thereof at one side and by the bracket arm 103 at the opposite side. The

, lever 137 is of the first order and its forward arm is inclined downward to overlie the head 1331 of the lever arm 133, while the rearwardly extending arm of said lever 137 is adapted to contact with an underlying shoulder 139 formed on la vertically disposed arm or member 140 which member further comprises a vertically disposed Portion 141 below the shoulder 139. The member-comprising the parts 139- 141 is at its upper end pivotally connected to and depends from a headed pivot pin 142 which is riveted to a lug or extension 87 d projecting laterally outward from the part 87a of the carrier 87 above the hook 88. The shoulder portion 139 is generally horizontal but inclines slightly upward and forward terminating in a rounded portion which connects with the' straight lower arm 141. The under edge of the rear end ortion of the lever 137 is straight and it is t iis straight portion which is adapt- -ed to contact with the rounded forward part of the shoulder referred to above. From Figs. 1 and 7 it will be apparent'that this contact between the lever 137 and the shoulder 139 takes place directly above the pivotal axis of the dog carrier which axis passes through the pivots 80 and 81, and also' that normally the contact point is almQSQ horizontal rearward from the pivotal axis of the lever 137. Because of this disposition of the parts the impulse of the lever 137 applied to the arm 139-141 will be downward sub stantially in the vertical plane containing the dog carrier axis, and consequently this impulse will not-tend to turn the dogcar rier on its pivots but will only operate to turn thel carrier part 87 on its pivotal axis 86 with the effect hereinafter described.l The lower arm portion 141 is guided between the adjacent ears 78 and a headed stud or pin 143 and may -be pointed to facilitate initial entrance therebetween. Said pin and said ear revent lateral dis lacement of the depen ing member whi e outward displacement thereof away from the face of the carrier on which it slides is prevented by the head of the stud 143. It will be understood that the spring 99 acts through the carrier part 87 and the device 139-141 attached thereto to swing the lever 137 on its pivot by reason of the upward pressure of the shoulder or off-set 139 on the lever 137. In other words, the spring 99 acts as a restoring spring not only for the carrier part 87 but also for the lever 137. This restoring movement of the lever 137 is limited by a stop pin 144 which projects laterally from the arm 103 into the path of the rear arm of said lever 137. In operation, when the space bar key 129 is depressed, rocking the spacing frame and swinging upward the arm 133 about the axis 131, the head 133a will move upward and forward acting against the under side of the forward arm of the lever 137, swinging said lever on its fulcrum 138 and causing the rear arm of said level', acting on the shoul-- der 139, to depress the arm 140. The downward movement of the arm 140 will be transmitted'to the carrier part 87 which will be swung downward about its pivotal center 86 until arrested by the engagement of the upper and inner side of the hole 91 with the nut or stop 90, as shown in Fig. 8, which it will be recalled is a rear view. As a result of this downward movement of the carrier part 87, the dogs or detents 92 and 93 carried by it will also be moved bodily downward to an extent which carries the dog 92 below and out of the path of the escapement wheel teeth 46, the dog 93 being moved downward so that its tooth portion 93a will be brought into the path of the rear or overhanging portions of said wheel teeth. In other words, the dog 92 is carried down out of the contact plane of the teeth of the rack membergfl (which may be said to be represented by the horizontal plane indicated by the dotted line 6-6 in Fig. 8) Vand the dog 93 is lowered into the plane of said teeth. The normal po: sition of the tooth 93a is clearly shown in rigs. 2 and 7 and it will be understood from these figures that not only is said tooth above and out 0f the path of the escapement Wheel teeth 46 but that also it is held by the spring 97 at the right (viewed from the rear) of the tooth 46 engaged by the dog 92. The consequence is that when the carrier part 87 is lowered so as to carry the dog 92 out of the contact plane of the escapement wheel and to bring the dog tooth 93a into said contact plane, i. e., the path of the rear part of the teeth46, the escapement wheel will be free to turn in the direction of the arf row in Fig. 2 until .the next or proximate tooth 46 in its advance engages with the dog tooth 938L and overcoming the spring 97 swings the third dog 93 on itspivotal axis 95 toward the left as viewed from the rear until the dogr 93 completes its pivotal movement, atwhlch time the parts will be in the position shown in Figs. 8 and 9. From Fig. 8 it will be seen that the pivotal movement of the dog member 93 is arrested by the engagement of the nose 93b with the dog 92 and by the engagement of the outer face of said dog with the shoulder 87b of the carrier part 87. The described movement of the dog 93 and escapement wheel 45 is sulficient in extent to permita letter space movement of the carriage under the pull of the carriage motor, and from what has been said it will be clear that this letter space advance of the carriage will be fully completed during the depression of the space key 129, providing what is termed a full-drop escapement. When the space key is released the carrier 87 will be restored or swung upward to normal position as illustrated in Fig. 2, carrying the dog tooth 93a upward out of the ath of the escapement wheel teeth and ringing the dog 92 into the path of said teeth. As soon as the tooth 93a clears the escapement wheel teeth the dog 93 will be swung back to normal position on its pivot 95 through the action of the dog spring 97. From Fig. 8 it will be plain that, since the working faces of the two dogs 93 and 92 are substantially in alignment in the abnormal position of the parts when the space bar is held depressed and since the dog 92 is at the limit of its leftward movement at this time, there will be no escapement movement of the wheel 45 when the dog tooth 93"l moves out of engagement with the engaged tooth 46 and the dog 92 moves into engagement therewith. It will be noted that the working face of the dog tooth 93, which is the righthand face viewed from the rear, is straight so that it may effectively co-operate with the straight working faces of the escapement wheel teeth; and that preferably the rear or working face of the tooth 93a is provided with a clearance bevel. From what has been said it will be apparent that the independent vibration of the secondary carrier 87, that is, its pivotal movement about the center 86 from the Figs. 2, 7 position to the Figs. 8', 9 position and back again to the `first position,

will take place substantially in a plane of the escapement wheel, the working faces of the dog members 92 and 93 both vibrating in the plane of the working face of the wheel teeth and both operating in said plane under actuation of the space key to effect a reverse i feed escapement movement in co-operation with two successive escapement wheel teeth. It will further be understood that the space key may be depressed to afford a letter space feeding movement of the carriage` and that while held depressed, with the parts of the escapement related as illustrated in Figs. 8 and 9, a printing key may be operated causing the associate type bar to print, and operating the escapement mechanism to effect a letter feed advance movement of the carriage on the' return stroke of the printing key. Such escapement movement will take place as a result of swinging the rocker 77 on its pivots carrying the engaged dog tooth 93L rearward out of the escapement wheel and bringing the beveled or holding dog 85, into engagement with the front side of said tooth, holding the escapement wheel temporarily against turning movement. As soon as the dog tooth 93a has been swung rearward far enough to clear the escapement wheel the dog 93 will be turned rightward (as shown in Fig. 8) on the pivot 95 under the impulse of the dog spring 97 until said dog 93 is arrested by the stop 88 in such position that when a printing key is released and the rocker 77 swings back, the dog tooth 93l will enter the path of the wheel teeth 46 in posil0( tion to engage with the next oncoming tooth 46 which will co-operate with the tooth 93 to swing the dog 93 back to the Fig. 8 position, causing a letter' feed movement of the carriage during the upstroke of the printing 105 key. This action of the escapement mechanjsm under the impulse of a printing key has taken place it will be borne in mind while the space key is held depressed, and may be repeated as often as desired without releasll@ ing the Space key and without obstructing the printing or letter feeding movement of the carriage. In other words, so far as the effect on the carriage is concerned, the action of the escapement is the same under the im- 115 pulse of the printing keys. whether the space bar is in normal or in abnormal position, in one case the dog member 92 functioning as a stepping dog while in the other case the dog member 93 so funttions. From Fig. 8 it will 120 be apparent that at one stage tbe working faces of all of the dog members may be brought into a single plane passing through nated', these having been primarily due in prior constructions to the faulty operation of the escapement under the actuation of the space bar. Such prior constructions have been inherently slow because of the fact that operators are not usually sol speedy with the thumb as with the fingers, the thumb being habitually employed to actuate the space bar; and f or this reason as well as for the further reason that/there is a common tendency on the part/'of operators to dwell on the space bar, productions of spreads 'or the printing of characters in what should be blank spaces, is quite prevalent. Obviating this defect and preventing the writing of spreads is accomplished in the present instance by providing a space key mechanism which causes a full letter space movement when the space key is depressed and which does notrequire that the space key shall return or start to return to normal position to effect such movement. Even, therefore, should the operator dwell on the space bar at the bottom of the stroke the spacing of the carriage will have taken place. Moreover, the printing of additional characters may be accomplished before the space bar returns to normal position. In addition to the spring 99, suitable spring .mechanism may be provided for restoring the space key mechanism to normal position, if found desirable.

Suitable detent devices may be provided for preventing undue backward rotation of the escapement wheel, such devices being illustrated in Figs. 2 and 6 and comprising an angular plate-like detent member 145, which is horizontally arranged upon the bed plate 9 at one side of the escapement wheel and is provided with an angularly disposed downwardly extending tongue 146 which is adapted for co-operation with the escapement wheel teeth. The plate 145 is formed with a round hole, indicated at 147, and a slot indicated at 148, the slot being open at one end and receiving a headed screw 149, which is provided with a long shoulder portion 150 and a reduced end or shank 151 which is threaded into the bed plate. The hole 147 receives a headed screw 152 having a short shoulder153 and a shank 154 which is only partly threaded into the bed plate. Underlying the detent plate 145 is a plate spring 155 which is clamped at one end to the bed plate by the shoulder 150 and at its opposite end is arched upward as indicated at l156, the arched portion bein formed with a hole with which the expose portion of the shank 154 engages, said hole, however, being smaller in diameter than the shoulder 153 which it underlies, the result being that the'upward tendency of the free arched end of the spring 155 1s limited by the shoulder 153. In operation, when the escapement Wheel 45 turns in the direction of the arrow in Fig. 2 the points of the teeth 46, acting against the inner curved face of the tongue 146, will swing the member 145,

146 pivotally, said member fulcruming on the spring arch 156, its free end moving upward guided by the shoulder 150, the spring or yielding fulcrum promoting free turning movements of the escapement wheel. Each tooth 46 as it moves downward exerts a camming action against the inner face of the tongue 146, pushing it out of the way far enough to allow the tooth to pass, the action resulting in a vibration or risingvand falling ofthe detent plate 145, 146 as the result of co-operation with itof each successive wheel tooth. Backward turning movements of the escapement wheel, however, are prevented by reason of the contact of the backs of the wheel teeth 46 with the ends of the tongue 146. Each time the wheel tooth contacts with said tongue it will lift the plate 145 until the latter is arrested by the under side of the head of the screw 152 which thereafter acts as a positive stop preventing further retraction of the wheel.

As a result of my invention prior constructions have been greatly simplified, the number of necessary parts being considerably reduced, and the action of the escapement'has also been improved both in respect toi; certainty and ease of operation. Moreover, the mechanism is constructed to alford ready access to all of the parts, thusl promoting assembling and adjustment. This important feature of the construction will be readily appreciated from an inspection of Fig. 11 which shows the dog carrier parts 77 and 87 disconnected to ail'ord access to the dogs 92 and 93 and the spring 97. This disconnection is effected by unscrewing the screw 86 which enables the part 87 to be dismounted from its support, the hole 91 being made of suiicient size to pass readily over the hexagonal head of the nut. 90, so that the relationship between the adjusted screw 89 and its support need not be disturbed. It will be observed that the parts 92, 93 and 97 are thus fully exposed and since these parts are loosely mounted they may be readily slipped into and out of place avoiding the usual requirement of manipulating additional connecting and securing devices such as screws, spring hooks, and the like. The carrier arts 87 and 77 are readily connected by t e replacing of the screw 86, the carrier part 87 bearing on the shoulder portion of said screw and the shank thereof being threaded into a tapped hole in the support or carrier part 77.

Various changes may be made without departing from my invention.

What I claim as new and desire to secure by Letters Patent, is,

1. In an escapement mechanism for typewriting machines having printing keys and a space key, the combination of a toothed escapement wheel, a dog carrier, and three escapement dogs, certain of said three dogs co-operatimr with successive teeth of said escapement lw ieel to afford a. no-drop feed of the 'traveling carriage of the machine, and certain of said dogs co-operating with successive teeth of said escapement wheel to afford a full-drop feeding movement of said traveling carriage, one of said three dogs being'alwa'ys operatife by all of the keys of the machine, each of' the other` two dogs being operative by certain keys only of the machine.

2. In a typeWriting machine, the combination of printing keys, a space key, a toothed escapement wheel, a dog carrier and a plurality of dogs, certain of said dogs cooperating under actuation of said printing keys with said successive teeth of said escapement wheel to afford an ordinary or no-drop feed of the traveling carriage and certain of said dogs co-operating under actuation of the space. key with the successive teeth of said escapement wheel to afford full-drop feeding movements of said traveling carriage.

3. In a typewriting machine, the comblnation of a traveling carriage, keys, a toothed escapement wheel, a dog carrier, a holding dog, a stepping dog, and a third dog, certain of said keys being effective to cause said holding dog and said stepping dog to co-operate with successive teeth of said escapement Wheel to afford no-drop escapement movements of the carriage and certain other of said keys being effective to cause said stepping dog and said third dog to co-operate with successive teeth of said vescapement wheel to afford full-drop escapement movements of said carriage.

4. In escapement mechanism for typewriting machines, the combination of a rack member, a pivoted dog carrier vibratable transversely of the plane of said rack member, and a plurality of dogs mounted on said dog carrier, certain of. said dogs being pivotally supported and being vibratable at the same side of their pivotalsupport in the plane ofv said rack member and into and out of engagement with the teeth thereof.

5. In escapement mechanism for typewriting machines, the combination of a rack member, a pivoted dog carrier vibratable transversely of the plane of said rack member, and a plurality of dogs mounted on said dog carrier, certain of said dogs being pivotally supported and being vibratable at the same side of their pivotal support in the plane of said rack member into and out of engagement therewith, such vibration of said dogs about their pivotal support taking place while said dog carrier is quiescent.

6.In escapement mechanism for typewriting machines, the combination of a rack member, a pivoted dog carrier vibratable transversely of the plane of said rack.mem ber, and a plurality of dogs mounted on said dog carrier, certain of said dogs being pivotally supported and beingl vibratable at the Same side of their pivotal support into and out of engagement with said rack member, such vibration of said dogs about their pivotal support takin place while said dog carrier 1s quiescent tbut all of said dogs moving wlthv said dog carrier when it is rocked transversely of the plane of said rack member.

i. In escapement mechanism for typewriting machlnes, the combination of printlng keys, a rack member, a pivoted dog carrier vibratable transversely of the plane of said rack member, and a plurality of dogs mounted on said do carrier, certain of said dogs being pivotal y supported and being vibratable at the same side of their pivotal support into and out of said rack member, such vibration of said dogs about their pivotal support taking place while said dog carrier is quiescent but all of said dogs movlng with said dog carrier when it is rocked transversely of the plane of said rack member by said printing keys.

8 In escapement mechanism for typewrlting machines, the combination of printing keys, a space key, a rack member, a plvoted dog carrier vibratable transversely of the plane of said rack member, and a plurality of dogs mounted on said dog carrier, certain of said dogs being pivotally supported and being vibratable at the same side of their pivotal support into and out of said rack member under the actuation of said` space key only and while said dog carrier is quiescent but all of said dogs moving with said dog carrier when it is rocked transversely of the plane of 'said rack member by said printing keys.

9. In escapement mechanism for typewriting machines, the combination of a rac-k member, a plate-like main dog carrier, a secondary dog carrier also plate-like in form, and escapement dogs confined between said main and secondary dog carriers.

1 0: In escapement mechanism 'for typewritlng machines, the combination of a rack member, a plate-like main dog carrier, a secondary dog carrier, and escapement dogs confined between said main and secondary dog carriers, certain keys of the machine operating both main and secondary dog carriers and certain other keys operating only one of said dog carriers.

11. In escapement mechanism for typewriting machines, the combination of a rack member, a plate-like main dog carrier, a secondary dog carrier, escapement vdogs confined between said main and secondary dog carriers, and a spring effective on both of said dogs and also confined between said plate-like carriers.

12. In escapement mechanism for typewriting machines, the combiriation of `a carrier part, and

vmember, a plate-like main rack member, a plate-like main dog carrier, a secondary plate-like dog carrier, and escapement dogs confined between said main and secondary dog carriers, said dogs serving as stops for one another.

13. In escapement mechanism .for typewriting machines, the combination of a rack member, a two-part dog carrier comprising plate-like parts, and escapement dogs confined between said carrier parts, said dogs serving as stops for one another in one direction, the carrier parts serving as stops for said dogs in the opposite direction.

14. In escapement mechanism for typewriting machines, the combination of a pivoted main dog carrier part, a secondary dog carrier part pivoted to said main part, dogs arranged between and controlled by said carrier parts, and a stop Xed to said main part for limiting pivotal movements of said secondary part thereon.

15. In escapement mechanism for typewriting machines, the combination of a rack member, a plate-like main dog carrler, a secondary dog carrier, said secondary part being also plate-like in form and having a portion offset from said main part to provide a recess or pocket, and dogs arranged in said recess.

16. In escapement mechanism for typewriting machines, the combination of a rack dog carrier, a secondary dog carrier, said secondary part being also plate-like in form and having a portion offset from said main part to provide a recess or pocket, dogs arranged in said r e cess, and a spring loosely disposed 1n said recess and effective on both of said dogs.

17. In escapement mechanism-for typewriting machines,the combination of a rack member, a dog carrier part, a dog thereon, a second dog carrier part pivoted on said first two dogs on said second carrier part, one of said two dogs being normally in the contact plane of the teeth of the rack member and the other of said two dogs having its working face normally behind said contact plane.

18. In escapement mechanism for typewriting machines, the combination of .a toothed escapement wheel, a dog carrier v1- bratable transversely of the plane of said wheel, a. dog thereon normally forward of ythe plane of said wheel, a second part pivoted to said carrier part, two dogs pivoted on said second part both normally in the plane of said escapement wheel but one normally at one side of the contact plane of the teeth of said wheel, and key operated means for vibrating said second part independently of said first recited carrier part.

19. In escapement mechanism for typewriting machines, the combination of an escapement wheel having an axle, a dog carrier comprising two parts, one pivoted on the other, three dogs mounted on said dog carrier, and key operated means effective on certain of said dogs to cause a no-drop escapement ,and also effective on certain of said dogs to cause a full-drop escapement, both styles of escapement being caused by cooperation of the dogs with successive teeth of the escapement wheel, all of said dogs being adapted in the course of operation to be brought into a single plane containing the axle of said escapement wheel.

2.0'. In escapement mechanism for typewriting machines, the combination of a rack member, a `pivoted main dog carrier, a secondary dog carrier pivoted on said main carrier, a holding dog rigid with said main carrier, a stepping dog pivoted on said secondary carrier and in susbtantially the same plane transverse of said rack member as said holding dog, and a third dog pivoted to said secondary dog carrier and having its engaging face normally above the plane of contact with the teeth of said rack member.

21. In escapement mechanism for typewriting machines, the combination of a circular rack member having teeth projecting both radially and laterally from its body portion, a key operated dog carrier, and a plurality of escapement dogs mounted on said dog carrier, the working portion of one of said dogs being offset and co-operative with offset portions of the teeth of the rack member.

22. In escapement mechanism for typewriting machines, the combination of an eS- capement wheel provided with teeth which project radially and also have engaging portions offset laterally, a dog carrier, and a dog mounted on said dog carrier and provided with an offset tooth which is normally out of engagement with the said offset portions of the radially projecting teeth,

23. In escapement mechanism for typewriting machines, the combination ,of a vertically disposed escapement wheel provided with radial teeth, a dog carrier pivotally mounted below said escapement wheel, a pair of dogs mounted on said dog carrier and adapted to co-operate with the wheel teeth at the under side of said escapement Wheel, and a third dog having an angularly projecting tooth which normally is received in a circular groove or depression formed in one of the faces of said escapement wheel.

24. In escapement mechanism for typewriting machines, the combination of a twopart dog carrier, dogs confined between the parts of said carrier, and disconnectible means connecting said carrier parts, said dogs being adapted to drop out of place when said carrier parts are disconnected.

25. In escapement mechanism for typewriting machines, the combination of a twopart do carrier, a screw pivotally connecting sait? parts, studs on one of said carrier ilo parts, escapement dogs loose on said studs and held against displacement by the other carrier part, and stop devices limiting relative movement between said carrier parts, said screw being detachable to permit separation of said parts and the removal of said dogs from said studs.

26. In escapement mechanism for typewriting machines, the combination of a two part dog carrier, a screw pivotally connecting said parts, pivots n one of said carrier parts, escapement dogs loose on said pivots and held against displacement by the other carrier part, a loosely mounted dog spring, and stop devices limiting relative movement between said carrier parts, said screw being detachable to permit separation of said parts and the removal of said dogs Jfrom said pivots and also the removal of said dog spring.

27. In escapement mechanism for typewriting machines, the combination of a rack member, a key operated pivotally mounted dog carrier comprising two parts, one pivotyed on` the other, dogs on said dog carrier,

and a restoring spring effective both to move one of said carrier parts relatively to the other and also to restore said dog carrier as a whole from abnormal to normal position.

28. In escapement mechanism fory type` .writing machines, the combination of' an p pivoted on said first carrier part to vibrate in a plane substantially parallel with the lane of said escapement wheel, stops limit- 1ng the relative pivotal movement of said parts, dogs on said carrier parts, and a spring connected to said secondary carrier part and effective to restore it to normal relationship with the first carrier part after vibration Vin the plane of said wheel, said spring being also effective to restore said first carrier part to normal position after vibration transversely of said wheel;

29. In escapement mechanism for typewriting machines, the combination of a rack member, a ivoted main dog carrier part, a secondary og carrier part pivoted to said lil prising a lever adapted to co-operate with the shoulder portion of said arm directly above the pivotal aXis of said main carrier art. A p y30. In escapement mechanism for typewriting machines, the combination of a rack member, a pivoted dog carrier, a secondary dog carrier movably supported on said main carrier, escapement dogs, certain of said dogs being mounted on said main carrier and certain of said dogs being mounted on said secondary carrier, a key, and operative connections etween said key and said secondary carrier comprising two coacting parts which contact above the axis of said main carrier and substantially in the vertical plane containing said axis.

31. In a typewriting machine, the combination of a toothed escapement wheel; es-

capement dogs; and detent devices co-operative with the teeth of said wheel to prevent undue backward rotation thereof, said detentl devices comprising an angular plate having a tongue portion co-operating directly with the backs of said teeth, shouldered screws with which said plate loosely col-operates, and a leaf vspring which resiliently supports said plate.

32. In a typewriting machine, the combination of a toothed escapement wheel; escapement dogs; and detent devices co-operative with the teeth of said wheel to prevent undue backward rotation thereof, said detent devices comprising a loosely mounted plate having a tongue portion co-operating directly with the backs of said teeth, and a leaf spring which resiliently supports said plate and also provides a pivot therefor.

Signed at the borough of Manhattan, city of New York, in the county of New York and State of New York, this 10th day of June,`A. D. 1921.

` ARTHUR W. SMITH. Witnesses:

CHARLES E. SMITH,

E. M. WELLS. 

